The Nor-Ray-Vac system consists of an AmbiRad SmartCom³ controller with a black bulb sensor, either an Inverter style* or standard local** relay unit housed in an IP54 rated metal enclosure, a pump(s) [fan], and a specified number of Nor-Ray-Vac LR burners.
The SmartCom3 panel is a sophisticated microprocessor based energy controller designed for highly accurate time and temperature switching to give optimum fuel economy.
Each SmartCom3 panel contains a clear digital display for monitoring system operation and a means of setting the various system parameters by way of ten push buttons. Temperature control is carried out by a black bulb radiant sensor, mounted in a ventilated enclosure, sited up to 100 metres away.
In addition, the SmartCom³ MZ can be set up for multiple zone installation using Master and Slave function linked via data cable to provide multiple or split zone operation.
For B80/B160 & B300 fans*, the local relay unit houses the inverter. This unit converts the 230V single phase input into a soft start three phase 230V output which extends the motor life by minimising the starting current. On the panel fascia, there is a panel live lamp (red) and a fan healthy (amber). Each Inverter local relay unit must be positioned either max 5m from the fan for EMC class ‘A’ buildings or max 10m for EMC class ‘B’ buildings.
For BH300 fans**, the local relay unit houses a fan contactor and overload. On the panel fascia, there is a panel live lamp (red) and a fan trip (amber).
Fans are designed into the system on an individual basis.
The B80/B160/B300 fan MUST be wired in delta whilst the BH300 MUST be wired in star.
The controller will send a voltage supply to the end vent burner(s) and close a volt free circuit to the LRU when the following conditions are met:
a) power to the SmartCom³ and local relay unit are live and isolators are in the ON position.
b) SmartCom³ temperature set point value is higher than room temperature.
c) SmartCom³ time is within day time settings (or night set back temp is in operation).
d) SmartCom³ mode is set to Heat Only.
e) black bulb stat is operating and wired correctly back to the controller.
When all the above conditions are ok, a delay of some 30 seconds will occur prior to sending a voltage supply to the end vent burner(s) and close a volt free circuit to the LRU.
The fan will start.
The vacuum induced by the fan will cause the internal pressure switch within the end burner to make circuit allowing power to an onboard timer and after a preset delay, onto the electronic sequence controller to light the burner. A signal will simultaneously be sent to any inline burner(s) on that radiant branch where again allowing an onboard timer to delay a signal onto the electronic sequence controller to light the burner. The burner closest to the exhaust fan in each radiant branch will light first. Each subsequent burner will light at 25 second intervals until finally the end vent will light.
Once the black bulb sensor is satisfied, power is lost to the burners and they will switch off. However the fan will continue to run for some 3 minutes to allow a cooling down period and exhaust of combustion products. If the system recalls for heat, the same sequence will start over again.
In split zone systems (where a singular fan is operating two or more zones), the operation for starting the Nor-Ray-Vac system is identical to above. However, where one zone is satisfied and another zone calls for heat, the pressure switch has to sense a positive pressure therefore the fan has to stop to allow the vacuum to dissipate. An electronic circuit within the control panel removes the supply voltage to all the burners in all zones as well as the fan for 30 seconds. The power is then reapplied and the starting sequence starts over again.
Please refer to separate documentation for the setting of the SmartCom³ (doc ref GB/SCOM/120/0709) and Interconnecting and setting manual (doc ref GB/CON/004/0212)